Terry Pratchett

By irreducibly complex I mean a single system composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning.

The bravest person I've ever met was a young boy going through massive amounts of treatment for a very rare, complex and unpleasant disease. I last saw him at a Discworld convention, where he chose to take part in a game as an assassin. He died not long afterwards, and I wish I had his fortitude and sense of style.